Shower P-Trap Above Unheated Garage

[Brewer Sands]

I've worked my way through the posts on supply piping to above garage rooms, and will be running the pipes through the heated envelope, but haven't seen much on dealing with shower traps in (insulated) joist bays above an unheated garage (in Ontario, Canada).

I was hoping to have get some insights on best way to deal with freezing risk for a shower trap. Regards.

Brewer Sands

 

[Reach4]

You adjust the insulation to put the trap on the warm side away from the garage.

 

[Sponsor]

 

[Jadnashua]

You adjust the insulation to put the trap on the warm side away from the garage.

Depending on the joist depth, the drain assembly, and the trap used, there may be essentially no room for insulation beneath the trap. What size are the joists?

While the garage may not be heated, are the walls insulated? Unless the door was left open for extended periods, it may not be an issue.